This has already been successfully done by Roland DGA with their Picza series of scanners. The one I have has what appears to be a very long sewing needle attached to the piezo by means of solder. Instead of reinventing the wheel, you might want to just buy a replacement piezo/probe sensor from Roland directly. They've already done all of the research to engineer a working probe...you'll have to come up with your own electronics.
-Brady |